Virtual reality is often used to describe a wide variety of applications commonly associated with immersive, highly visual, computer-simulated environments that can simulate a user's physical presence in places in the real world or imagined worlds. While virtual reality can recreate a number of sensory experiences, the senses most commonly used today to create virtual reality appear to be sight and sound.
One method of presenting a virtual world to a user that is commonly identified with virtual reality and presently in use is through the use of a visor or helmet containing a video display which encompasses part or all of a user's field of view and presents computer generated images representing the virtual reality environment, or “virtual world,” to the user. Such a device is often referred to as a head-mounted display, or HMD. One type of HMD presently available is the Oculus Rift from Oculus VR, now owned by Facebook.
Typically a HMD covers the user's eyes, so that the user sees only the virtual world while wearing the HMD and is thus unable to see the actual physical world around the user while in the virtual world. For this reason, the use of a HMD can create some issues when it is necessary or desirable that the user interact with, or sometimes not interact with, the real world. Since the user cannot see the real environment, the user may not know what actions by the user should occur in the real world, and what actions may have detrimental consequences in the real world.
One instance of such an issue may arise when the user wishes to be able to use some type of input device while in the virtual world. For example, a user may wish to use a handheld controller, such as might be used to play a video game, while in a virtual world, and perhaps even two controllers, one for each hand. However, since the user cannot see the physical world once he or she is wearing the HMD, it can be difficult for the user to locate and pick up the controller after putting on the HMD, as the user must blindly fumble around the physical environment to locate the controller(s).
Alternatively, it can be difficult to pick up and put on a HMD if the user has already picked up and is holding a controller in his or her hand, and even more so if there are two controllers. In this case, the user may drop one or more of the controller(s) or HMD, resulting in possible damage to the devices.
Another issue with respect to the user's interactions with the physical world is that it is difficult for the user to maintain awareness of his or her location in the physical world while the user sees only the virtual world. It may be desirable that the user remain within a selected area, for example, if there are physical objects in the vicinity of the user. The user may wish to be able to move within the virtual world by, for example, taking a step or moving an arm; of course, any such movement also results in the user moving in the physical world. When playing a conventional video game on a television, for example, even when using a controller which responds to the user's motion the user is able to see nearby objects, and avoid moving the controller in a way which causes the user to collide with such objects. However, when using a HMD the user is unable to see those nearby objects while in the virtual world, and may thus not be aware of impending collisions.
It is thus desirable to find a solution that will allow a user in a virtual world presented by a HMD to be aware of the user's physical surroundings to a sufficient degree to allow the user to pick up handheld controllers, and to remain in a selected area, for example to avoid collisions with surrounding physical objects.